MR. MONRO, aged 28, at No. 16, Featherstone Buildings, twelve years ago, had violent inflammation, occasioned by the lash of a whip striking the left eye, from which time he has been unable to see more than the shadow of an object. He says that many have advised him to submit to an operation for cataract, but others have recommended him not to do so as long as one eye remained sound. On the 16th of May, when he applied to me, I tried, as an experiment, the vapour of the prussic acid, which was employed for about three months. At the end of that time he could see different objects, and discern countenances, when the other eye was closed. Afterwards he went into the country, where he remained without using any medicine. On his return to town, on the 18th of January, 1843 he called upon me, when I found the eye was not improved in appearance. He is now again under my care, and has had the vapour applied five times. It appears to produce a very decided effect upon the vision. In three or four parts the cataract appears as if it had been operated upon with a couching needle. This is a case of great interest, and it is impossible for any unprejudiced person to doubt the great absorbent powers of prussic acid in many diseases of the eye; but I am certain it will not be a general remedy for lenticular cataract (unless employed in its incipient state) without operation, unless aided by rupturing the capsule of the lens by the needle first. Many are the cases where we want such a solvent power after operations. CASE 12. _Amaurosis._ ANN WEEKS, of No. 19, Little Queen Street, aged 14, daughter of Thomas Weeks, carman, 52, Great Wilde Street, has been blind in her right eye since she was two years old. The left eye is unaffected. When two years of age she was taken to an Ophthalmic Hospital, where various modes of treatment were adopted for the recovery of the eye, until the month of March, 1842, when she went to another Ophthalmic Hospital, where she attended for six months, but received no benefit. On the 16th of June the Rev. Peter Hall, of Long Acre Chapel, brought her to me; and when examined in a strong light, with her face towards the window, we could not perceive the slightest action of the pupil. Mr. Hall and I tried her with a sheet of white paper, moving it before her eyes several times, but she was perfectly unconscious of it. After the eye was exposed to the vapour of prussic acid for a short time the pupil acted slightly when exposed to light; and she was able, not only to see the paper, but to take hold of it with her hand, and could walk round the table when the left eye was shut. She continued the vapour four or five times weekly for the space of six weeks. When she left me the eye was so far recovered as to answer all ordinary purposes of vision, although not quite equal to the other. I have examined her to-day (Jan. 20, 1843), and find the improvement continues. CASE 13. _Amaurosis._